Vintage motorcycle engine

[Countach LP400]

Hi all. I have decided to build a brass-era style motorcycle from scratch over the summer, something like a Pope Single, and I am currently looking for an engine.

I don't know what to use....the standard Chinese engine would always work, but I'd rather have something that looks, feels, and sounds old. Moreover I would like to have manual spark advance, to make it feel completely vintage.

Naturally spark advance would have to be engineered, but what about sound, appearance, and feel? Are there any good engines that fit my needs?

Needless to say I can't afford a real brass era engine, though that would be perfect.

Thanks!

[eDJ]

You may locate some motorcycle junk yards around the country and find something from
the fifties or earlier that could be dressed up to look vintage. I've seen some old Benelli
and Gilera motors that look like throw backs to earlier times.

If you want to stay within the guidelines of a motorized bicycle you may have to stay
under 50cc, one horse power, one gear ratio, one rider, but that will depend on what state
you live in.

BikeBerry's 50cc has a fairly round cylinder and could look like an earlier motor where as those
with the square cylinder fins look more mid sixties and later. There are a few of those Russian
motors around yet, but they are expensive. They have a vintage look though.

I'm one who has been sitting around trying to figure out how to "antique" one of these Chinese
motors enough to make it look like an old original at a glance. But you'll still be having people
ask if it's a 1910 era bike or a reproduction. New chrome parts will quickly betray the fact that
it's a reproduction.

A belt drive will look like the bike is a pre 1913 or so where if you use a chain and sprocket
it will appear as a later bike.

These are just some things I've sorted out since I've been looking at a vintage build.

[Motoschwinn]

Well... One could look at changing the appearance of the Chinese motor. I've thought about this quite a bit. I think the biggest change I would like to make is altering the appearance of the clutch cover, and the magneto/clutch arm covers. I've toyed with using paints to do this, I think drab military colors would age the motor, and I've thought about having faux covers made. A sheet metal worker could really knock off some vintage style "cover-ups".

Of course, this doesn't help you in the sound a feel dept... I did a Google after reading your post, and vintage motors are outrageous!

[Countach LP400]

Thanks guys. I'm wondering if I should just get a regular 66cc (80) and machine a new cylinder and head, to make it look more old, along with the clutch cover etc. that Motoshwinn suggested. But again that wouldn't help me in the sound and feel department.

A Bellini would be fantastic, but I'm a tad concerned with finding service and parts for it.

The optimum choice would be some sort of low RPM agricultural engine, but finding one that is light and the right shape would be tricky.

Maybe I should just build my own, using a China engine as a starting point? If I could stroke it out, that might work. Do 2-cycles respond well to stroking?

[Motoschwinn]

I think Jim at Creative Engineering could answer that best. He's a very active user here.

[Motoschwinn]

Of course with time the china motor can look like this:

[fasteddy]

If I may toss out an idea. Being an antique dealer and some time car restorer I traveled to many steam and farm shows. You may be very surprised at the number of old motors for sale from lawn mowers,tillers ect.
The people selling them are usually very knowledgeble about parts supplies and getting them running.
Tell them what you are doing and I'm sure they will help all they can. Just be prepared for a lot of questions.
Steve.

[eDJ]

A while back I was on an Antique Motor Restoration site looking around. Most of the
stuff I saw wouldn't work but of that that could it was over 50cc and 1 hp.

The guys had parts by spec's more than PN's. But when stuff is that old finding parts
for it may have to be done with measurements as it may no longer be inventoried by
part numbers.

I like the idea of aftermarket cylinders & heads if anyone has the means to build such.

next to that is tooling plates of aluminum to cover & seal the sides of these Chinese
motors to make it appear more like an older motor. Fortunately the side covers in the
old days looked more like slabs of smoothe metal.

I'm sure if someone wanted to do it they could tool a cylinder head that would look
like the old 4 cycle engine flat head set ups even though they are 2 cycle.

One of the nice things about the Whizzer engine is the look of it. But the cost of them
will no doubt drive a market that makes low cost knock off's to dress up a cheap Chinese
HT motor. In time someone will prototype these things and go to China with it. Already
someone is making a knock off of those dual spring Monark forks, so you don't have to live
on eBay waiting to snipe them in the last few seconds.

But when someone starts making these frames that look like boardtrack racer frames (even
as kits for the buyer to weld) and motor dress up kits which will make a vintage looking
motor out of a stock HT, then more building of these Vintage look alikes will begin to
happen. And did I mention vintage looking fuel tanks and belt drive adapter kits too ?

These are the things that are missing in the market now. "Springer" forks are available as with
most of the rest of the stuff to build with.

[Countach LP400]

I think I have narrowed it down to 2 options.

I could either go with a Minarelli moped engine, or the motor from an old chainsaw. Ebay revealed to me that there is no shortage of cheap chainsaw engines from the 50s and earlier. The high displacement and torque are plusses, as are centrifugal clutches and light weight.

Chainsaws are ugly, but not as ugly as go-cart engines, and I am sure that I could dress one up with new plates, clutch covers, etc.

Luckily enough, I don't have to worry about engine size. California law states that it must produce 2 or less gross horsepower, but says nothing about displacement.

Of course I could just get both, a China engine and a chainsaw engine, and mess with them until I found the one that served me best.

[Creative Engineering]

Countach,

I would not consider building an engine powered bicycle with one of the old, large dispacement, chain saw engines.

These engines are powerfull, and they have a powerband! When this powerband kicks in; the bicycle is going to self destruct with you on it...I'm not a safety weenie...it's just a matter of fact.

I remember driving a racing go-gart years ago, (70's), that had a McCulloch 101 chain saw engine. When the powerband came in, (at 20 mph), it rocketed to 50 mph, and topped out at 70!

Consider the base hardware that you will be sitting on and riding...then put in an appropriate engine.

Jim